Automobiles often include self-diagnostic capabilities to detect problems that affect engine performance, emissions, braking, and other computer controlled or monitored vehicle systems. For example, when a vehicle control module associated with a vehicle system, circuit, or component detects a fault or sensor reading outside an acceptable predefined range, the control module may generate an alphanumeric diagnostic trouble code that identifies the fault and that may be saved as diagnostic data to memory in a vehicle computer. When certain diagnostic trouble codes are received by the vehicle computer, the computer will illuminate a warning indicator light within the vehicle, such as the widely used malfunction indicator light (MIL), better known as the “Check Engine” light, which provides a general indication that there is a problem with the vehicle. But such indicator lights may provide little or no value to a vehicle driver in determining the potential seriousness of any given problem and no directions or assistance are given on how to remedy the potential problem. Some vehicles are equipped to perform a diagnostic check and then display trouble codes, but this information is also of limited usefulness to a driver who is not familiar with the meaning of such codes. Another existing system provides a textual display instead of trouble codes and while this provides additional information to the vehicle driver, it requires the driver to divert his or her visual attention to the textual display and can be limited in its ability to assist the driver in taking remedial action to fix the problem.
In other existing vehicle diagnostic implementations, diagnostic information may be extracted from the vehicle computer by a service technician. For example, the service technician can place the vehicle computer into a diagnostic mode by grounding certain terminals on a diagnostic connector of the onboard computer, thereby causing the “Check Engine” light or other indicator lights to blink or otherwise display the specific fault code associated with the potential problem. In another example, a service technician may plug an electronic diagnostic scan tool into the diagnostic connector of the onboard computer to access and read fault codes in detail. In either case, the diagnostic trouble codes may be extracted but must be completed by a service technician using only a direct, physical connection to the vehicle.
More recently, other methods have been developed to provide remote analysis and communication with the vehicle and its diagnostic system using a live advisor. Such services are available for vehicles equipped with a factory-supplied, built-in cellular or other wireless communication system. Using this service, limited diagnostic information is supplied to the live advisor who can them give the vehicle user a recommendation as to how soon they need to take their vehicle in for servicing. This system can also be used to automatically communicate with a central call center in the event that the vehicle system detects certain events, such as a deployment of the vehicle airbags or other safety system.